Method and system for a wireless multi-hop relay network

Abstract

In a wireless multi-hop relay network arranged in a tree topology, the base station and one or more relay stations are associated as a virtual base station (VBS). The base station and each relay station have a unique virtual base station identifier (VBS-ID) associated with the path defined by the base station and the one or more relay stations. a relay station in the branch uses its VBS-ID for communicating with an attached subscriber station (e.g. a mobile station) such that communications between the base station and subscriber station occur via the VBS. Subscriber station data communications are relayed between the base station and the one or more relay stations over the VBS via a tunnel connection. The VBS is autoconfigurable. Mobility for subscriber stations and relay stations is provided through reconfiguration of VBS's.

We claim: 
     
       1. A relay station for use in a wireless multi-hop relay network arranged in a tree topology, wherein the relay station comprises:
 at least one antenna; 
 wherein the relay station is configured to:
 communicate with one or more subscriber stations via the at least one antenna using a unique identifier with which the relay station is associated, wherein the relay station is a last relay station in a branch, and wherein the branch comprises one or more relay stations coupled to a base station; 
 receive data for the one or more subscriber stations from the base station via a tunnel connection identifier, wherein the tunnel connection identifier is associated with a path defined by the base station and the one or more relay stations in the branch; and 
 perform attachment if the relay station is not attached to an upstream station, wherein to perform attachment, the relay station is further configured to: 
 receive a control information message from the upstream station; 
 send at least a first message to the upstream station; 
 receive at least a second message from the upstream station comprising the unique identifier for the relay station; and 
 exchange third messages to obtain the tunnel connection identifier. 
 
 
     
     
       2. The relay station of  claim 1 , wherein the relay station is configured to perform communication with a first subscriber station of the one or more subscriber stations if the relay station is attached to the upstream station, wherein to perform communication, the relay station is further configured to:
 receive control information and at least one data burst for the first subscriber station from the upstream station; and 
 send packets comprising the at least one data burst to the first subscriber station. 
 
     
     
       3. The relay station of  claim 1 , wherein the unique identifier for the relay station is associated with the path defined by the base station and the one or more relay stations in the branch. 
     
     
       4. The relay station of  claim 1 , wherein the branch comprising one or more relay stations coupled to the base station are associated as a first virtual base station (VBS). 
     
     
       5. The relay station of  claim 1 , wherein the relay station, in response to receipt of a message from an upstream station, is further configured to:
 search a routing table of the relay station for a received tunnel connection identifier; and 
 if the received tunnel connection identifier is in the routing table and associated with a first subscriber station of the one or more subscriber stations, remove the received tunnel connection identifier and forward the message to the first subscriber station via a connection identifier associated with the first subscriber station. 
 
     
     
       6. The relay station of  claim 5 , wherein the relay station is further configured to:
 if the received tunnel connection identifier is not in the routing table, drop the message; and 
 if the received tunnel connection identifier is in the routing table and associated with a unique identifier that is associated with another relay station, forward the message to the another relay station. 
 
     
     
       7. The relay station of  claim 1 , wherein the third messages are not tunneled. 
     
     
       8. A method for use in a wireless multi-hop relay network arranged in a tree topology, the method comprising:
 by a relay station, 
 communicating with one or more subscriber stations using a unique identifier with which the relay station is associated, wherein the relay station is a last relay station in a branch, and wherein the branch comprises one or more relay stations coupled to a base station; 
 receiving data for the one or more subscriber stations from the base station via a tunnel connection identifier, wherein the tunnel connection identifier is associated with a path defined by the base station and the one or more relay stations in the branch; and 
 performing attachment if the relay station is not attached to an upstream station, wherein said performing attachment comprising:
 receiving a control information message from the upstream station; 
 sending at least a first message to the upstream station; 
 receiving at least a second message from the upstream station comprising the unique identifier for the relay station; and 
 exchanging third messages to obtain the tunnel connection identifier. 
 
 
     
     
       9. The method of  claim 8 , wherein performing communication with a first subscriber station of the one or more subscriber stations if the relay station is attached to the upstream station, wherein said performing communication comprises:
 receiving control information and at least one data burst for the first subscriber station from the upstream station; and 
 sending packets comprising the at least one data burst to the first subscriber station. 
 
     
     
       10. The method of  claim 8 , wherein the unique identifier for the relay station is associated with the path defined by the base station and the one or more relay stations in the branch. 
     
     
       11. The method of  claim 8 , wherein the branch comprising one or more relay stations coupled to the base station are associated as a first virtual base station (VBS). 
     
     
       12. The method of  claim 8 , further comprising, in response to receipt of a message from the upstream station by the relay station:
 the relay station performing:
 searching a routing table of the relay station for a received tunnel connection identifier; and 
 if the received tunnel connection identifier is in the routing table and the received tunnel connection identifier is associated with a first subscriber station of the one or more subscriber stations, removing the received tunnel connection identifier and forwarding the message to the first subscriber station via a connection identifier associated with the first subscriber station. 
 
 
     
     
       13. The method of  claim 12 , further comprising:
 the relay station performing:
 dropping the message if the received tunnel connection identifier is not in the routing; and 
 if the received tunnel connection identifier is in the routing table and the received tunnel connection identifier is associated with a unique identifier that is associated with another relay station, forwarding the message to the another relay station. 
 
 
     
     
       14. The method of  claim 8 , wherein the third messages are not tunneled. 
     
     
       15. An apparatus for use in a wireless multi-hop relay network arranged in a tree topology, the apparatus comprising:
 a relay station, wherein the relay station is the last relay station in a branch, wherein the branch comprises one or more relay stations coupled to a base station, wherein the relay station has an associated unique identifier for communicating with at least one subscriber station, wherein the relay station receives data for the at least one subscriber station from the base station via a tunnel connection identifier, wherein the tunnel connection identifier is associated with a path defined by the base station and the one or more relay stations in the branch, and wherein the relay station comprises logic to perform attachment if the relay station is not attached to an upstream station, wherein attachment comprises:
 receiving a control information message from the upstream station; 
 sending at least a first message to the upstream station; 
 receiving at least a second message from the upstream station comprising the unique identifier for the relay station; and 
 exchanging third messages to obtain the tunnel connection identifier. 
 
 
     
     
       16. The apparatus of  claim 15 , wherein the relay station further comprises logic to perform communication with the at least one subscriber station if the relay station is attached to the upstream station, wherein communication comprises:
 receiving control information and at least one data burst for the at least one subscriber station from the upstream station; and 
 sending packets comprising the at least one data burst to the at least one subscriber station. 
 
     
     
       17. The apparatus of  claim 15 , wherein the unique identifier for the relay station is associated with the path defined by the base station and the one or more relay stations in the branch. 
     
     
       18. The apparatus of  claim 15 , wherein the branch comprising one or more relay stations coupled to a base station are associated as a first virtual base station (VBS). 
     
     
       19. The apparatus of  claim 15 , wherein the relay station further comprises logic to receive a message from the upstream station, wherein in response to receipt of the message, the relay station further comprises logic for:
 searching a routing table of the relay station for a received tunnel connection identifier; and 
 if the received tunnel connection identifier is in the routing table and is associated with the at least one subscriber station, removing the received tunnel connection identifier and forwarding the message to the at least one subscriber station via a connection identifier associated with the at least one subscriber station. 
 
     
     
       20. The apparatus of  claim 19 , wherein logic in the relay station further comprises logic for:
 if the received tunnel connection identifier is not in the routing table, dropping the message; and 
 if the received tunnel connection identifier is in the routing table and is associated with a unique identifier that is associated with another relay station, forwarding the message to the another relay station.